Potentially useful biochemical indices of zinc nutriture will be evaluated and normal ranges for these indices will be established during all stages of pregnancy. These indices will be used to evaluate maternal zinc status in selected pregnancies and during lactation. It is proposed to determine if there is a correlation between the zinc nutriture of lactating women and the zinc content of their milk. Current studies of zinc nutriture in infants will be extended to include the breast-fed and the premature infant and patients with failure to thrive. Studies of zinc nutriture and zinc supplementation in pre-school children will be designed to determine if zinc deficiency is one environmental factor contributing to the poor growth of some population groups. Zinc nutriture and metabolism will be investigated in children in the following specific circumstances: delayed puberty, juvenile rheumatoid arthritis, diabetes mellitus, malabsorption syndromes, sickle cell disease, learning disorders, intravenous nutrition, adenocorticosteroid therapy. Investigations in acrodermatitis enteropathica will include studies designed to localize the inherited molecular defect and further studies of leukocyte function. Investigations of copper nutriture will be undertaken simultaneously with the zinc studies, especially in the premature infant.